I've only had it change once so far (I was 8), but when my progressed ascendant changed to Cancer, my mother filed for divorce. I became the defacto mother to my two younger siblings, due to my mother (the custodial parent) being horrifically mentally ill and unfit for the challenges of single motherhood.

I would definitely look at the other aspects in your progressed chart for a better idea of what form your new ascendant is going to take. in my progressed chart at that time, i had sun conjunct saturn in eighth, and moon in the third house in a square to pluto in fifth.

That's an excellent point about aspects. I have a t-square between the 10th house Moon, 12th house Sun and 4th house Pluto/Uranus.

you can get through them, the extra sensitivity is the first sign.  persevere      

One difference I have noticed is when my Progressed Ascendant was in Cancer every time the Moon was in Cancer I would eat everything in sight. I could literally tell without looking that the Moon was in Cancer, I don't do that at all now. Interesting.

That's not right my progressed Moon is in Virgo. Dazed and confused

OMG! I can sooooooooooooooooooooooo relate. Except with me it's my p.Moon in Cancer

It's taken me a few months to adjust to this placement, but basically I noticed that when I get EMOTIONALLY HUNGRY

And if I don't address the void or feelings at that precise moment (using Mercury)

I find myself trying to vacuum pack the perceived empty space with food ....

Like gorging myself to stupor